Reds manager Jurgen Klopp downplayed the severity of the injury, which has allowed Daniel Sturridge to make a rare league start.
Klopp suggested the injury that led to the Brazilian being sidelined was "not a big thing."
“Actually, yesterday after training he mentioned a little muscle issue. We'll assess it obviously. It’s not a big thing but was enough to leave him out today, that’s all,” Klopp told Sky Sports ahead of Friday’s kick-off.
Firmino has appeared in 46 games for Klopp’s men this year, notching 16 goals and eight assists.
He has four goals in 10 Champions League games, bagging one in each leg of their quarter-final win over Porto, as well as his only assist in the competition in the first leg of that tie.
The 27-year-old, who has 28 international caps for Brazil with nine goals, starred in last year’s semi-final win over Roma with two goals and two assists in the 5-2 victory in the first leg, before providing another assist in the 4-2 loss in the second.
Firmino’s goals tally is the third-highest for the club this year, behind the other two members of their front three, Mohamed Salah (23) and Sadio Mane (22).
His replacement in the side for the Huddersfield game, Sturridge, has made just two Premier League starts for the club this campaign, though this will be his second against Huddersfield.
Sturridge has made the starting XI just twice in the Champions League, scoring in Liverpool’s first group game, a 3-2 win over PSG in September.
Besides Sturridge, Klopp’s other option for centre-forward, should Firmino’s injury be more severe than the German believes, is Divock Origi.
The 24-year-old Belgium international has appeared in 16 games this season, making just five starts, and has found the back of the net three times.
Liverpool defeated Huddersfield 5-0 to return to the top of the table and put pressure on title rivals Manchester City, who began the weekend one point clear.
City don’t play until Sunday, when they face Burnley at Turf Moor.